A new coating method named emulsion phase-inversion coating for preparing microcapsules containing hydrogel beads was reported in our previous work. In this paper, we suggest a numerical model for predicting the coating process. By defining suitable dimensionless parameters, the governing equation and its associated initial and boundary conditions are discretized using Euler's differential equation and the system of resulting differential equations is simultaneously solved using MATLAB for the dimensionless coating thickness and water content in beads. Parametric studies show that the dimensionless coating thickness depends on the dimensionless critical concentration, an internal property of the hydrogel beads, which can be calculated using the dimensionless final coating thickness. In addition, the apparent diffusion coefficient of water in coating layers can be easily obtained by fitting our experimental data to the simulated results. The comparison experiments show that there is a good agreement between the predicted and experimental coating thickness with the fitted apparent diffusion coefficient. The model also reveals that the apparent diffusion coefficient when using Polyacryinitrile (PAN) is far smaller than that when using Polysulphone (PSf) as the coating polymer, resulting in a relatively thinner and more hydrophilic coating layer, which suggested that we could modulate the physiochemical properties of the coating layers by changing the coating polymer. (c) 2005 Elsevier Ltd. All rights reserved.